Hitachi CL32W35TAN Serviceanleitung Seite 37

Test Point ID Net Name
A195 VX
A206 VX
A218 VX
A219
A230 GNDD
A205 VR
A142 VR
A132 VR
A169 /RVLC
A180 /LC
A207
A117 TXD-
A131 VREF
A115 CF2
A102 CF1
A178 RXI-
A179 RXI+
A182
A162 5v-AMODEM
A228 GNDD
A103 EXTAL
A086 XTAL
A078 TEST2/RCLK
A074 /RTS
A069 HD5
A084 HD6
A085 HD7
A203 /MODEM RESET
A100 HA0
A105 HA1
A101 HA2
A089 /HIRQ
A088 /HRD
A095 /HWR
A083 HD0
A076 HD1
A082 /HCS
A094 XTAL1
A099 XTAL2
A073 D4
A072 D3
A077 D2
A113 RXD
TP900 /SHUNT
A114 TXD
A130 RING
A149
A148
A232 OFFHOOK
A126
A233
A174
A193 /OH
Function
isolated input from telephone @ 2V
scaled down vesion of A195
AC coupled vesion of A206 to 2.5V DC (A131)
AC gnd for inverter
gnd for DAA
reduced amplitude version of A142
AC coupled version of A132 to 2V DC
audio signal to appear across phone lines
mirror (reduced) of voltage across the phone line
0V = offhook, 5V = onhook
feedback for buffer
inverted signal for transmit to phone (not used)
reference voltage (2.5V when comunicating)
internal feedback integration filter
internal feedback integration filter
inverted receive input
non-inverted receive inpunt
feedback virtual gnd
analogue 5V
gnd
cyrstal oscillator input: 24.576MHz
cyrstal oscillator: 24.576MHz
0V unused input
5V unused input
modem data line 5
modem data line 6
modem data line 7
0V = reset modem data pump IC
modem address line 0
modem address line 1
modem address line 2
host interupt request
host read enable strobe
host write enable strobe
modem data line 0
modem data line 1
host chip select
cyrstal oscillator input: 14.7456MHz
cyrstal oscillator: 14.7456MHz
modem data line 4
modem data line 3
modem data line 2
5V RS232 from mips to modem
pulse dial shunt relay output (not used)
5V RS232 to mips from modem
ring detect input
voltage reference 0.65V
mirror (reduced) of voltage across the phone line used to detect ringing signal
parallel phone offhok detect - 1s pulse low = parallel phone offhook
parallel phone offhook streached pulse
parallel phone offhook short pulse
0V = offhook, 5V = onhook
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